Chapter 4

Improperly obtained evidence

The section 30 balancing exercise

4.6 The application of the test in s 30 and its precursor, the R v Shaheed test, have been subjected to criticism by commentators.262 The criticism is grounded in the lack of guidance as to how these tests should be applied, including the weight, interpretation and application of the relevant factors.263 There is concern that “s 30 may simply ‘permit the personal predilections of judges to masquerade as principle and … sanction little more than a judicial ‘gut check’ [in] respect [of] the decision to exclude’”.264 Similar reservations are that s 30 turns criminal trials into “lotteries”265 dependent on the personal inclination of a particular judge.266 Opinion is divided as to whether uncertainty in the application of s 30 is unavoidable267 or could be ameliorated by adherence to mutually agreed principle.268 Further criticisms relate to either the courts’ approach to the balancing exercise itself or their interpretation and application of the specific factors listed in s 30(3).269

4.7Commentators have also indicated concern that some factors are given primacy over others. In particular, R v Hawea270 is cited as an instance where the nature and quality of the evidence (subs 3(c)) and the seriousness of the offence (subs 3(d)) were prioritised over other s 30 factors.271

4.8As a first step, a judge must determine, on the balance of probabilities, whether the disputed evidence was “improperly obtained” as defined in subs (5). If the judge finds that evidence was improperly obtained, he or she must determine whether exclusion of the evidence would be proportionate to the impropriety, having regard to the factors listed in subs (3). This balancing process must be one that “gives appropriate weight to the impropriety but also takes proper account of the need for an effective and credible system of justice”.272

4.9 Courts have repeatedly stated that strict rules cannot be laid down to guide the judge.273 Rather, admissibility will always require a proceeding-specific assessment274 as the inquiry under s 30 will very much depend on the facts.275

4.10The evaluative nature of the s 30 balancing process means that different judges may come to different conclusions on the same evidence. As Gault J stated in Hamed “[a]ll of the factors specified in s 30(3) call for value judgments that may well depend on inclinations of particular judges, as will the comparative weighting to be accorded those factors”.276 This is aptly demonstrated by the number of judgments and appeals on the application of s 30 to date. It is likewise evident from Hamed, the only Supreme Court case to have considered s 30 in detail, where admissibility fell to be determined by differently constituted majorities on the different types of evidence.

4.11The s 30 balancing process is necessarily fact specific. Factors such as “the nature of the impropriety”, the “nature and quality of the improperly obtained evidence” and “whether there was any urgency” will always need to be determined by reference to the facts in a given case. A degree of uncertainty is also implicit in a multi-faceted balancing approach. In relation to each factor, a judge must determine whether it is relevant, whether it favours admission or exclusion, and what weight to ascribe to it. Only then can these factors be balanced against each other to determine whether exclusion is a proportionate response to the impropriety.

4.12Two observations can be made against this background:

The fact specific nature of the s 30 inquiry does not preclude courts from making general statements to guide admissibility. Indeed, the Court of Appeal did just that in R v Williams when it set out to “assist trial judges in determining the weight and relevance to be given to each statutory factor in the circumstances of a particular case”.277The Court also made the following generalisations that courts have subsequently found useful to apply:278

Thus, where a breach is minor, the balancing exercise would often lead to evidence being admissible where the crime is serious and the evidence is reliable, highly probative and crucial to the prosecution case. The exclusion of evidence in such cases would properly be seen as unbalanced and disproportionate to the circumstances of the breach.

By contrast, if the illegality or unreasonableness is serious, the nature of the privacy interest strong, and the seriousness of the breach has not been diminished by any mitigating factors such as attenuation of causation or a weak personal connection to the property searched or seized, then any balancing exercise would normally lead to the exclusion of the evidence, even where the crime was serious. This result would be almost inevitable where the breach was deliberate, reckless or grossly careless on the part of the police – see Shaheed at [148]–[149].

A systematic approach to the s 30 balancing process encourages clear and transparent decision making. This, in turn, is likely to lead to increased certainty and consistency in the application of s 30 over time.

4.13Certain general principles have already emerged in the application of s 30. This is confirmed by commentators who have stated that “judgments under the proportionality-balancing test have fallen into patterns that are reasonably predictable and subject to rational discernment”.279

4.14 Our view is that, generally, judges are conscientious in their approach to s 30 and seek to articulate the factors that favour admission and those that favour exclusion. Courts have also been very clear that s 30 requires a balancing of all relevant factors, and are conscious that disproportionate weight cannot be given to any one factor.280 This is borne out by cases that have excluded real and probative evidence even where very serious offending is involved.281

4.15We emphasise the importance of courts setting out clear reasoning for decisions under s 30 and endorse the direction by Elias CJ in Hamed for “conscientious disclosure of the full reasons for decision”.282 A systematic process whereby courts clearly articulate the factors considered and the weight attached to each will aid in the development of jurisprudence in this area and lead to more consistent decision making.

4.16There are undoubtedly some areas where interpretation of the factors in subs (3) has not yet fully settled. By way of example (and by no means seeking to set out a comprehensive list):

Are there circumstances where a “serious” offence should be considered a factor that favours exclusion rather than inclusion?284

Should the centrality of the disputed evidence to the prosecution’s case be considered in light of the Select Committee’s amendment to paragraph (c)?285

Does the fact that there were / were not alternative techniques available favour admission or exclusion?286

4.17Our view is that the multi-faceted nature of the decision making process under s 30 necessarily involves difficult questions of judgment that are not amenable to scientific precision. However, our view is that, over time, further general principles will emerge to assist courts with the balancing exercise in s 30. We have therefore been cautious about recommending legislative change that could impede the courts’ progress to achieving clarity in this area. Matters such as those identified above should be clarified over time.

4.18One possible drafting issue, however, was highlighted by the Supreme Court in Hamed. Subsection (2)(b) requires the proportionality inquiry to be conducted via “a balancing process that gives appropriate weight to the impropriety butalso takes proper account of the need for an effective and credible system of justice” (emphasis added). The use of the word “but” seems to suggest that an effective and credible system of justice is a counterpoint to the impropriety that points towards admissibility. As Elias CJ succinctly puts it:287

“[T]he need for an effective and credible system of justice” is not a consideration that points only to admissibility (as suggested by the erroneous view that s 30(2)(b) requires a balance to be struck between the impropriety and “the need for an effective and credible system of justice”).

4.19As their Honours note, an effective and credible system of justice also gives substantive effect to human rights and the rule of law288 and does not condone police impropriety in obtaining evidence.289 We agree. Replacing the word “but” with “and” would better reflect the relevance of an “effective and credible system of justice”.

4.20We have considered whether amendment is necessary given that courts generally do not seem to have had any problems with interpreting the subsection as intended. Indeed, a number of cases have explicitly stated that exclusion of evidence is consistent with “an effective and credible system of justice”.290 However, the amendment is desirable to avoid the perception that an effective and credible justice system in New Zealand is one that is aimed only at the prosecution and conviction of offenders. The Supreme Court’s pronouncement on the issue in Hamed should ensure that the amendment is interpreted appropriately.

R8 We recommend amending s 30(2)(b) to read “if the Judge finds that the evidence has been improperly obtained, determine whether or not the exclusion of the evidence is proportionate to the impropriety by means of a balancing process that gives appropriate weight to the impropriety and takes proper account of the need for an effective and credible system of justice.”

279Scott Optican “‘Lessons from Down Under’: The Exclusion of Improperly Obtained Evidence in New Zealand as a Model for a Changing United States Exclusionary Rule” [2011] JCCL 226 at 248. See also Optican and Sankoff “Reliability/ Oppression/ Improperly Obtained Evidence”, above n 262, at 152.